Inquire: Call 0086-755-23203480, or reach out via the form below/your sales contact to discuss our design, manufacturing, and assembly capabilities.
Quote: Email your PCB files to Sales@pcbsync.com (Preferred for large files) or submit online. We will contact you promptly. Please ensure your email is correct.
Notes: For PCB fabrication, we require PCB design file in Gerber RS-274X format (most preferred), *.PCB/DDB (Protel, inform your program version) format or *.BRD (Eagle) format. For PCB assembly, we require PCB design file in above mentioned format, drilling file and BOM. Click to download BOM template To avoid file missing, please include all files into one folder and compress it into .zip or .rar format.
Nelco N4000-6: Standard FR-4 Laminate for General PCB Applications
In the evolving landscape of PCB design, the term “Standard FR-4” can be misleading. For engineers working on high-reliability systems, “standard” doesn’t mean basic; it means a proven, consistent baseline. Nelco N4000-6 fits this description perfectly—a high-Tg, multifunctional epoxy laminate that has become a staple for complex, high-layer-count designs.
While many designers are rushing toward ultra-low-loss materials for 112G and beyond, the vast majority of industrial, automotive, and infrastructure projects require a robust, thermally stable substrate that won’t delaminate during rework or fail in harsh environments. This is where N4000-6 shines.
Nelco N4000-6 is a high-glass-transition temperature (Tg 175°C) multifunctional epoxy system. Developed by Park Electrochemical (now part of the AGC Multi Material family), it was engineered specifically to solve the reliability issues inherent in traditional low-Tg FR-4 when exposed to modern thermal stresses.
Unlike standard FR-4 which might soften or expand excessively during soldering, N4000-6 maintains its structural integrity. It is widely considered an “enhanced” FR-4 because it uses multifunctional epoxy resins that provide superior thermal and chemical resistance compared to the difunctional resins found in cheap, entry-level boards.
Key Performance Attributes
High Thermal Stability: With a Tg of 175°C (DSC), it thrives in lead-free assembly environments.
Low Z-Axis Expansion: Crucial for preventing barrel cracking in high-aspect-ratio vias.
CAF Resistance: Inherently resistant to Conductive Anodic Filament growth, essential for long-term reliability in humid conditions.
Processing Ease: It handles like standard FR-4 in the shop, meaning no special drilling or desmear equipment is required.
Technical Specifications: N4000-6 at a Glance
When we evaluate a laminate from an engineering perspective, we look at the “big three”: Thermal, Electrical, and Mechanical properties. The table below summarizes the critical data points for Nelco PCB N4000-6.
Property
Typical Value
Test Method
Glass Transition (Tg)
175°C (DSC) / 170°C (TMA)
IPC-TM-650
Decomposition Temp (Td)
325°C
TGA (5% wt loss)
Z-Axis Expansion (< Tg)
50 – 60 ppm/°C
TMA
Total Expansion (50-260°C)
3.7%
TMA
Dielectric Constant (Dk)
4.1 @ 1 GHz
RF Impedance
Dissipation Factor (Df)
0.022 @ 1 GHz
RF Impedance
Moisture Absorption
0.10%
IPC-TM-650 2.6.2.1
Peel Strength (1oz Cu)
9.0 lb/inch
IPC-TM-650 2.4.8
Thermal Reliability and Lead-Free Compatibility
The transition to lead-free soldering (SAC305) pushed peak reflow temperatures from 220°C to 260°C. For a standard 140°C Tg material, this is a “death zone.” Nelco N4000-6 was designed to mitigate this.
Why Z-Axis Expansion Matters
In a multilayer board, the copper plated-through-hole (PTH) acts like a rivet. When the board is heated, the laminate expands much faster than the copper. If the material expands too much (high CTE), it puts immense tensile stress on the via barrel.
N4000-6 features a Z-axis expansion of only 3.7% between 50°C and 260°C. Compared to standard FR-4 which can exceed 6%, this reduced expansion significantly lowers the risk of internal via fractures during multiple reflow cycles or manual rework operations.
T260 and T288 Performance
Time to delamination (T260 and T288) is the ultimate test of resin-to-glass adhesion. N4000-6 typically survives T260 tests for 30+ minutes and T288 for over 5 minutes. This provides a massive safety margin for “thick” backplanes and high-density interconnects (HDI) that require multiple lamination cycles.
Processing Guidelines for Fabrication
One of the biggest advantages of N4000-6 is that it doesn’t require “exotic” fabrication steps. It is a favorite among PCB shops because it is predictable.
Drilling and Desmear
Because it is a multifunctional epoxy, it is slightly harder than standard FR-4 but much easier than polyimide or high-speed PTFE materials.
Drilling: Standard carbide bits are effective. The high Tg prevents “resin smear” from coating the inner layer copper during the drill stroke.
Desmear: Compatible with standard permanganate chemical desmear. It exhibits consistent etch-back, ensuring a strong “three-point connection” for internal copper layers.
Lamination Parameters
To achieve full cure and optimal properties, the lamination cycle must be carefully controlled.
Press Temperature: 182°C (360°F) for at least 60-90 minutes.
Pressure: 200–300 psi depending on the board complexity.
Cool Down: Controlled ramp-down is essential to prevent internal stresses and board warpage (bow and twist).
Typical Applications for Nelco N4000-6
Where do you find this material? It’s rarely in a cheap consumer toy, but you will find it in:
Automotive Under-the-Hood: Where vibrations and thermal cycling are extreme.
High-End Servers and Storage: For backplanes and line cards that require high layer counts (20+ layers).
Wireless Infrastructure: Base stations and power amplifiers where stability is key.
Industrial Control Systems: Where the board must last 15–20 years in a factory environment.
Useful Resources for Engineers
If you are currently designing with or sourcing Nelco materials, these resources are vital for your database:
FAQ: Frequently Asked Questions about Nelco N4000-6
1. Is Nelco N4000-6 lead-free compatible?
Yes. While its Td (325°C) is slightly lower than “lead-free extreme” materials like N4000-29, it is fully compatible with standard lead-free reflow profiles and is widely used in RoHS-compliant assemblies.
2. How does N4000-6 compare to N4000-13?
N4000-13 is a “Low-Loss” version of the resin system. If your signals are above 5 GHz, you should consider N4000-13. For general-purpose digital and power applications, N4000-6 is the more cost-effective and rugged choice.
3. What is the shelf life of N4000-6 prepreg?
Like most B-stage epoxy materials, prepreg should be stored in a climate-controlled environment (<23°C and <50% RH) for up to 3 months. For extended storage (6 months), refrigeration below 5°C is required.
4. Can I use N4000-6 for HDI designs with microvias?
Yes. Its high Tg and Low-CTE make it excellent for blind and buried microvia designs. It is compatible with laser drilling and provides a stable landing pad for plating.
5. What is the standard thickness for N4000-6 cores?
Cores are available in a wide variety of constructions, from 2.0 mils (0.05 mm) to 60+ mils (1.50+ mm). Always consult your fabricator for their current glass-style inventory to match your impedance model.
Final Engineering Verdict
For most “serious” electronics, Nelco N4000-6 is the safe, high-reliability choice. It represents the best balance of thermal stability, mechanical robustness, and fabrication yield. Whether you are building an automotive controller or a 24-layer backplane, N4000-6 provides the consistent foundation required to ensure your design lasts a lifetime.
Inquire: Call 0086-755-23203480, or reach out via the form below/your sales contact to discuss our design, manufacturing, and assembly capabilities.
Quote: Email your PCB files to Sales@pcbsync.com (Preferred for large files) or submit online. We will contact you promptly. Please ensure your email is correct.
Notes: For PCB fabrication, we require PCB design file in Gerber RS-274X format (most preferred), *.PCB/DDB (Protel, inform your program version) format or *.BRD (Eagle) format. For PCB assembly, we require PCB design file in above mentioned format, drilling file and BOM. Click to download BOM template To avoid file missing, please include all files into one folder and compress it into .zip or .rar format.
